IL294116B1 - Radiation detector and associated manufacturing method - Google Patents

Radiation detector and associated manufacturing method

Info

Publication number
IL294116B1
IL294116B1 IL294116A IL29411622A IL294116B1 IL 294116 B1 IL294116 B1 IL 294116B1 IL 294116 A IL294116 A IL 294116A IL 29411622 A IL29411622 A IL 29411622A IL 294116 B1 IL294116 B1 IL 294116B1
Authority
IL
Israel
Prior art keywords
layer
doping
gap
type
contact layer
Prior art date
Application number
IL294116A
Other languages
Hebrew (he)
Other versions
IL294116B2 (en
IL294116A (en
Original Assignee
Thales Sa
Commissariat Energie Atomique
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Thales Sa, Commissariat Energie Atomique filed Critical Thales Sa
Publication of IL294116A publication Critical patent/IL294116A/en
Publication of IL294116B1 publication Critical patent/IL294116B1/en
Publication of IL294116B2 publication Critical patent/IL294116B2/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
    • H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
    • H01L31/102—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier
    • H01L31/109—Devices sensitive to infrared, visible or ultraviolet radiation characterised by only one potential barrier the potential barrier being of the PN heterojunction type
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/0248—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies
    • H01L31/0256—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof characterised by their semiconductor bodies characterised by the material
    • H01L31/0264—Inorganic materials
    • H01L31/0304—Inorganic materials including, apart from doping materials or other impurities, only AIIIBV compounds
    • H01L31/03046—Inorganic materials including, apart from doping materials or other impurities, only AIIIBV compounds including ternary or quaternary compounds, e.g. GaAlAs, InGaAs, InGaAsP
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/08—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors
    • H01L31/10—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof in which radiation controls flow of current through the device, e.g. photoresistors characterised by potential barriers, e.g. phototransistors
    • H01L31/101—Devices sensitive to infrared, visible or ultraviolet radiation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/18—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof
    • H01L31/184—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof the active layers comprising only AIIIBV compounds, e.g. GaAs, InP
    • H01L31/1844—Processes or apparatus specially adapted for the manufacture or treatment of these devices or of parts thereof the active layers comprising only AIIIBV compounds, e.g. GaAs, InP comprising ternary or quaternary compounds, e.g. Ga Al As, In Ga As P
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Hardware Design (AREA)
  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Electromagnetism (AREA)
  • General Physics & Mathematics (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Power Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Chemical & Material Sciences (AREA)
  • Inorganic Chemistry (AREA)
  • Light Receiving Elements (AREA)
  • Solid State Image Pick-Up Elements (AREA)
  • Measurement Of Radiation (AREA)

Description

WO 2021/122931 1 PCT/EP2020/086687 DESCRIPTION TITLE: Radiation Detector and Associated Manufacturing Method FIELD OF THE INVENTION id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1" id="p-1"
[0001] The present invention relates to the field of infrared (IR) imaging, and in particular to a radiation detector or photodetector manufactured with III-V materials and operating at a temperature higher than 80 K.
PRIOR ART id="p-2" id="p-2" id="p-2" id="p-2" id="p-2" id="p-2" id="p-2" id="p-2"
[0002] It is known that in order to obtain high-performance imagers in the field of IR detection, the detector must operate at cryogenic temperatures, which requires the installation of cryogenic circuitry consisting, inter alia, of a cryostat and a refrigerating machine. id="p-3" id="p-3" id="p-3" id="p-3" id="p-3" id="p-3" id="p-3" id="p-3"
[0003] One of the essential problems of these detectors is the increase in the operating temperature in order to satisfy requirements of compactness, reliability, reduction of consumption and manufacturing costs of the refrigerating machine and the cryostat. The aim is to reduce the size, weight and consumption power of the cryogenic circuitry installed around the detector (SWaP criteria, standing for "Size, Weight and Power"). An infrared imager consists of a matrix of photodetectors hybridized onto a silicon reading circuit. id="p-4" id="p-4" id="p-4" id="p-4" id="p-4" id="p-4" id="p-4" id="p-4"
[0004] The main physical quantity of the photodetector which is linked to its operating temperature is its dark current Id, that is to say the current present in the component in the absence of illumination. Figure 1 presents the two mechanisms that limit the dark current Id of a photodetector to the bias voltage on a logarithmic scale and as a function of the inverse of the temperature T: the predominant phenomenon at low temperature is the generation-recombination current in the depletion zone, and the dominant phenomenon at higher temperature is the diffusion current in the flat bands. The two mechanisms cross over at a temperature Tc, defining two zones DIF and G-R. Above Tc (zone DIF), the dark current is limited by the diffusion mechanisms, and below Tc (zone G-R) by the generation-recombination mechanisms. The generation-recombination GR current originates from the generation of electron/hole pairs by means of SRH (Shockley- WO 2021/122931 2 PCT/EP2020/086687 Read-Hall) defects in the gap in the zones having a field initially located at the junction between the absorbent layer and the contact. The diffusion current originates from the generation of electron/hole pairs by means of SRH defects and/or a third charge carrier (Auger effect 1 or 7) and/or the absorption of a photon (radiative effect linked to the thermodynamic equilibrium of the detector with its environment). id="p-5" id="p-5" id="p-5" id="p-5" id="p-5" id="p-5" id="p-5" id="p-5"
[0005] It is therefore desirable to produce a HOT (High Operating Temperature) imager operating at a temperature of more than 80 K, for which the IR detector is limited only by the diffusion current, regardless of the temperature range. id="p-6" id="p-6" id="p-6" id="p-6" id="p-6" id="p-6" id="p-6" id="p-6"
[0006] For example, in the MWIR [3.7 µm - 5 µm], the majority of imagers currently marketed are made from InSb (III-V material) manufactured in implanted planar technology and operating at around 80 K, and therefore are not HOT imagers. In the MWIR [3.7 µm - 4.1 µm], a HOT imager in "XBn" technology, which is described below, operates at 150 K. Documents EP1642345, EP2002487, EP2249400 and EP2797122 describe an example of a so-called "XBn" HOT photodetector having a reduced GR current. It is generally manufactured by molecular beam epitaxy (MBE) and consists of the following stack: X = contact of InAsSb, n or p doping, or GaSb, p doping / B = barrier of AlGaAsSb / n = absorbent zone of InAsSb. The barrier B has the highest gap. id="p-7" id="p-7" id="p-7" id="p-7" id="p-7" id="p-7" id="p-7" id="p-7"
[0007] This component differs from traditional PN homojunctions made from InSb material because its architecture makes it possible to confine the depletion zone, which is the source of a strong dark current, outside the "small-gap" materials such as InAsSb (absorbent zone) and in a larger-gap material AlGaAsSb (the barrier). InAsSb is then in a so-called "flat band" regime, referring to the energy bands of the minority carriers of the absorbent zone. Adjustment of the thickness and the doping of the barrier B, for a given contact, allows the absorbent layer to remain "flat-band". The small-gap material (absorbent zone) thus remains electric field-free, which allows the component to have a low dark current and to operate at 150 K. When the material X is GaSb, the structure has a higher "turn-on voltage" (bias voltage), which leads to extra consumption of the IR imager. id="p-8" id="p-8" id="p-8" id="p-8" id="p-8" id="p-8" id="p-8" id="p-8"
[0008] These components of the XBn type have a certain number of drawbacks: WO 2021/122931 3 PCT/EP2020/086687 id="p-9" id="p-9" id="p-9" id="p-9" id="p-9" id="p-9" id="p-9" id="p-9"
[0009] - The material AlGaAsSb (barrier) is difficult to control. id="p-10" id="p-10" id="p-10" id="p-10" id="p-10" id="p-10" id="p-10" id="p-10"
[0010] - Growth and doping: aluminum-rich materials are known for being of inferior crystalline quality than materials based on indium or gallium (presence of numerous energy states in the gap). Furthermore, the optimum conditions for MBE growth of the layers of AlGaAsSb (barrier) and InAsSb (absorbent layer) are not the same, which means that compromises have to be made. AlGaAsSb doping is also difficult to control. id="p-11" id="p-11" id="p-11" id="p-11" id="p-11" id="p-11" id="p-11" id="p-11"
[0011] - Technological process: AlGaAsSb oxidizes readily in contact with air or water, which makes the technological procedure more complex. Passivation and the stabilization of the AlGaAsSb surface after etching in order to obtain a "shallow MESA" is difficult to carry out and may be a source of inhomogeneity (risk of loss of adhesion of the dielectric on AlGaAsSb because of its oxidation, fluctuation of the oxide at the edge of the mesas that may lead to current fluctuations, electrical crosstalk, etc.). id="p-12" id="p-12" id="p-12" id="p-12" id="p-12" id="p-12" id="p-12" id="p-12"
[0012] - The pixel formation is carried out by "shallow MESA" etching of the contact layer as far as the material AlGaAsSb, as illustrated in Figure 2. A common electrode 2 is deposited on the substrate 6, followed by an absorbent layer 3 of InAsSb, a barrier layer 4 of AlGaAsSb, and a contact layer 110. The contact layer 110 (p doping) is etched in order to delimit the pixels and is connected to metal contacts 65. id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13" id="p-13"
[0013] - Alignment of the offsets of the valence bands between InAsSb, AlGaAsSb and GaSb requires a bias voltage ("turn-on voltage") in order to be in a flat-band configuration. This configuration with a nonzero bias voltage may be a source of inhomogeneity, uncontrolled oxidation of the barrier being capable of generating a fluctuation of this characteristic voltage. id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14" id="p-14"
[0014] - The structure XBn cannot operate correctly in a matrix arrangement with pixels whose doping is carried out by diffusion. This is because with X = InAsSb being a small gap, there would be a nonnegligible leakage current along the axis X of the pixel zones (p-doped) toward the interpixel zones (n-doped). With X = GaSb, it would be necessary to apply a higher bias voltage because of the alignment of the valence band offsets, which increases the consumption of the WO 2021/122931 4 PCT/EP2020/086687 imager and is liable to cause numerous depolarization problems in the event of leaks, which is detrimental to the uniformity of the matrix. id="p-15" id="p-15" id="p-15" id="p-15" id="p-15" id="p-15" id="p-15" id="p-15"
[0015] In order to resolve some of these drawbacks, document FR 1601065 proposes an imager structure as illustrated in Figure 3. This structure has the advantage of being compatible with pixel formation by diffusion, implantation or recessing (localized etching to make contact with a buried barrier layer), as described in document FR1501985. id="p-16" id="p-16" id="p-16" id="p-16" id="p-16" id="p-16" id="p-16" id="p-16"
[0016] The photodetector comprises a stack 201 of different materials, comprising a small-gap absorbent layer corresponding to the smallest gap of the entire structure, a charge screen layer C2, a transition layer C3, a window layer C4, and a dielectric passivation layer C7. The layers C1 and C2 have doping of a first type, preferably n, and the layer C4 comprises zones P1 doped with the second type p, delimiting the pixels, and n-doped interpixel zones P2. id="p-17" id="p-17" id="p-17" id="p-17" id="p-17" id="p-17" id="p-17" id="p-17"
[0017] Residual doping of a material is defined as doping inherent to its manufacture and/or to the chemical nature of the material produced (ex uncontrolled impurities), which may be ascertained by measurements. Intentional doping is obtained by incorporating dopant atoms into the material. The incorporation may be carried out during the growth or after the growth by implantation or diffusion of dopant atoms into the material. id="p-18" id="p-18" id="p-18" id="p-18" id="p-18" id="p-18" id="p-18" id="p-18"
[0018] The interpixel n doping in the zones P2 is adjusted during the growth, while the p doping of the zones P1 is carried out by post-growth insertion of p-dopant atoms into the layer C4. id="p-19" id="p-19" id="p-19" id="p-19" id="p-19" id="p-19" id="p-19" id="p-19"
[0019] A metallization 25 establishes the contact with the zone P1 (first electrode). In such a structure, the absorbent layer C1 remains flat-band by the management of the doping and the thickness of the charge screen layer C2. id="p-20" id="p-20" id="p-20" id="p-20" id="p-20" id="p-20" id="p-20" id="p-20"
[0020] The structure of the bands of the layers C1, C2, C3 and C4 is configured not to form a barrier to movement of the minority carriers (which are holes in the case of n doping of the absorbent layer) from the layer C1 to the layer C4. The holes flow in the valence band and the electrons flow in the conduction band. In the case of n doping of C1, the bands of interest are the valence bands.
WO 2021/122931 5 PCT/EP2020/086687 id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21" id="p-21"
[0021] The semiconductor materials of the stack are materials based on IIIA and VA compounds of the periodic table of the elements. id="p-22" id="p-22" id="p-22" id="p-22" id="p-22" id="p-22" id="p-22" id="p-22"
[0022] On the other side (lower side), the stack conventionally comprises an n-doped intermediate layer C6 and an n-doped substrate C5 for forming the n-contact (second electrode). Their band structure is configured not to present a barrier liable to oppose movement of the majority carriers (the electrons in the case of n doping of the absorbent layer) from C1 to the second electrode. In the case of n doping of C1, the bands of interest are the conduction bands. id="p-23" id="p-23" id="p-23" id="p-23" id="p-23" id="p-23" id="p-23" id="p-23"
[0023] An example of this structure is: id="p-24" id="p-24" id="p-24" id="p-24" id="p-24" id="p-24" id="p-24" id="p-24"
[0024] contact window layer C4 of GaSb (n doping) / transition layer C3 of GaSb (residual p doping) / charge screen layer C2 of InAlAsSb (n) / absorbent layer Cof InAsSb (n). id="p-25" id="p-25" id="p-25" id="p-25" id="p-25" id="p-25" id="p-25" id="p-25"
[0025] The pixel formation is carried out by p-dopant diffusion or implantation into GaSb. id="p-26" id="p-26" id="p-26" id="p-26" id="p-26" id="p-26" id="p-26" id="p-26"
[0026] This type of structure has the following advantages: - no layer of AlGaAsSb (readily oxidizable and source of noise). - pixel formation by insertion of dopants, which allows simplified manufacture without "shallow MESA" etching and makes it possible to confine the minority charge carriers well in the interpixel, far from the dielectric C7 / C4 interface. - no characteristic voltage for establishing the current. This structure operates in photovoltaic mode because the heterostructures GaSb/InAlAsSb and InAlAsSb/InAsSb are of type 2. id="p-27" id="p-27" id="p-27" id="p-27" id="p-27" id="p-27" id="p-27" id="p-27"
[0027] Nevertheless, this structure has drawbacks: - the surface to be passivated is GaSb. Antimony-based materials are known to be difficult to passivate. There are risks of leaks on the surface and electrical crosstalk at the level of the lateral GaSb PN junctions (along the axis X between pixel zones and interpixel zones). - the incorporation of dopants by insertion, preferably by diffusion, into GaSb is not obvious, in particular by metal organic vapor phase epitaxy MOVPE.
WO 2021/122931 6 PCT/EP2020/086687 id="p-28" id="p-28" id="p-28" id="p-28" id="p-28" id="p-28" id="p-28" id="p-28"
[0028] It is an object of the present invention to overcome the aforementioned drawbacks by providing a radiation detector in the spirit of the detector described above but having improved manufacture and operation.
DESCRIPTION OF THE INVENTION id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29" id="p-29"
[0029] The present invention relates to a radiation detector comprising a stack of layers along a direction Z, said stack comprising: - an absorbent layer configured to absorb the radiation and made from a first semiconductor material having a first gap and doping of a first type, - a first contact layer made from a second material having a second gap strictly greater than the first gap, - an assembly consisting of at least one intermediate layer, referred to as an intermediate assembly, arranged between the absorbent layer and the first contact layer, each intermediate layer being made from an intermediate semiconductor material having an intermediate gap greater than or equal to the first gap, - an upper layer arranged on the first contact layer on the opposite side from said intermediate assembly, made from a third semiconductor material having a third gap strictly greater than all the other gaps of the stack, - the first contact layer and the upper layer having a plurality of detection zones and separation zones, a separation zone separating one detection zone from another detection zone, each detection zone being surrounded by a separation zone in a plane perpendicular to Z, a detection zone corresponding to a pixel of said detector, the second and third materials being configured to have doping of a second type in the detection zones and doping of the first type in the separation zones, - when the first doping type is n, a valence band of the first material is strictly less than a valence band of the second material in the detection zones, and the valence band or bands of the intermediate material or materials lie between the valence band of the first material and the valence band of the second material in the detection zones, and are configured to vary monotonically increasingly in the direction from the absorbent layer toward the first contact layer, WO 2021/122931 7 PCT/EP2020/086687 - when the first doping type is p, a conduction band of the first material is strictly greater than a conduction band of the second material in the detection zones, and the conduction band or bands of the intermediate material or materials lie between the conduction band of the first material and the conduction band of the second material in the detection zones, and are configured to vary monotonically decreasingly in the direction from the absorbent layer toward the first contact layer, - a passivation layer made from a dielectric material, arranged on the upper layer and having openings at the level of the detection zones of the upper layer, - the semiconductor layers of the stack being compounds based on elements of groups IIIA and VA of the periodic table of the elements, the second material comprising the VA element antimony and the third material not comprising the VA element antimony. id="p-30" id="p-30" id="p-30" id="p-30" id="p-30" id="p-30" id="p-30" id="p-30"
[0030] According to one embodiment: when the first doping type is n, the valence band(s) of the intermediate material or materials are less than the conduction band of the second material; when the first doping type is p, the conduction band(s) of the intermediate material or materials are greater than the valence band of the second material. id="p-31" id="p-31" id="p-31" id="p-31" id="p-31" id="p-31" id="p-31" id="p-31"
[0031] According to one embodiment: at the interface (12) between the upper layer and the contact layer in the detection zones: when the first doping type is n, the valence band of the third material lies below the valence band of the second material and the conduction band of the third material lies above the conduction band of the second material; when the first doping type is p, the conduction band of the third material lies above the conduction band of the second material and the valence band of the third material lies below the valence band of the second material. id="p-32" id="p-32" id="p-32" id="p-32" id="p-32" id="p-32" id="p-32" id="p-32"
[0032] According to one embodiment radiation detector as claimed in one of the preceding claims, wherein the third material is of the type III-As. id="p-33" id="p-33" id="p-33" id="p-33" id="p-33" id="p-33" id="p-33" id="p-33"
[0033] According to one embodiment, the second material is GaSb and the third material is InGaAs. Preferably, the percentage of indium of the third material is less than 50%. id="p-34" id="p-34" id="p-34" id="p-34" id="p-34" id="p-34" id="p-34" id="p-34"
[0034] According to one embodiment, the detector furthermore comprises: WO 2021/122931 8 PCT/EP2020/086687 - a second contact layer arranged below the absorbent layer and on the opposite side from the intermediate layer, made from a fourth semiconductor material having a fourth gap strictly greater than the first gap and doping of the first type, - a substrate on which the second contact layer is deposited. [ 0035] According to one variant, the doping of the second type of the detection zones is obtained by incorporation of dopant atoms into the contact layer and the upper layer, which is carried out after the growth of said contact layer and upper layer, and via said openings. [ 0036] According to one embodiment, the upper layer and the first contact layer have, in the detection zones and over their entire respective thickness, a quantity of dopant atoms greater than 1017 atoms/cm3. [ 0037] According to another aspect, the invention relates to a method for producing a radiation detector, comprising: - a step of producing a stack of layers along a direction Z on a substrate, comprising: - - an absorbent layer configured to absorb the radiation and made from a first semiconductor material having a first gap and doping of a first type, - - a first contact layer made from a second material having a second gap strictly greater than the first gap, - - a second contact layer made from a fourth semiconductor material having a fourth gap strictly greater than the first gap and doping of the first type, arranged between the substrate and the absorbent layer, - - an assembly consisting of at least one intermediate layer, referred to as an intermediate assembly, arranged between the absorbent layer and the first contact layer, each intermediate layer being made from an intermediate semiconductor material having an intermediate gap greater than the first gap, - - an upper layer arranged on the first contact layer on the opposite side from said intermediate assembly, made from a third semiconductor material having a third gap strictly greater than all the other gaps of the stack, - - a passivation layer made from a dielectric material, arranged on the upper layer, WO 2021/122931 9 PCT/EP2020/086687 - - the semiconductor layers of the stack being compounds based on elements of groups IIIA and VA of the periodic table of the elements, the second material comprising the VA element antimony and the third material not comprising the VA element antimony, - - the second and third materials being configured to have doping of the first type, - a step of forming openings in the passivation layer, - a step of incorporating dopant atoms into the first contact layer and into the upper layer via the openings, so as to form detection zones having a second doping type, the detection zones being separated by separation zones separating one detection zone from another detection zone, each detection zone being surrounded by a separation zone in a plane perpendicular to Z, a detection zone corresponding to a pixel of said detector, the second and third materials then having doping of the second type in the detection zones and doping of the first type in the separation zones, - a step (400) of metallization through the openings (Op) in order to form a first electrode (E1). [ 0038] According to one variant, the step of incorporating dopant atoms is carried out by diffusion. [ 0039] According to one embodiment, the first doping type is n and the dopant atom incorporated is zinc. [ 0040] According to one embodiment, the method according to the invention furthermore comprises, after the metallization step, a step of connecting a reading circuit to said stack via said first electrode. id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41" id="p-41"
[0041] According to one embodiment, the method furthermore comprises, after the step of producing the stack, a step of bonding a reading circuit to said stack, the step of forming the openings then being carried out through the reading circuit. id="p-42" id="p-42" id="p-42" id="p-42" id="p-42" id="p-42" id="p-42" id="p-42"
[0042] The following description presents several exemplary embodiments of the device of the invention: these examples do not limit the scope of the invention. These exemplary embodiments present both essential characteristics of the invention and additional characteristics linked to the embodiments considered.
WO 2021/122931 10 PCT/EP2020/086687 id="p-43" id="p-43" id="p-43" id="p-43" id="p-43" id="p-43" id="p-43" id="p-43"
[0043] The invention will be understood more clearly, and other characteristics, aims and advantages thereof will emerge during the following detailed description with reference to the appended drawings, which are given by way of nonlimiting examples and in which: id="p-44" id="p-44" id="p-44" id="p-44" id="p-44" id="p-44" id="p-44" id="p-44"
[0044] [Fig 1] Figure 1, already mentioned, illustrates the evolution of the dark current as a function of the temperature. id="p-45" id="p-45" id="p-45" id="p-45" id="p-45" id="p-45" id="p-45" id="p-45"
[0045] [Fig 2] Figure 2, already mentioned, illustrates the method of pixel formation by so-called "shallow MESA" etching. id="p-46" id="p-46" id="p-46" id="p-46" id="p-46" id="p-46" id="p-46" id="p-46"
[0046] [Fig 3] Figure 3, already mentioned, illustrates a photodetector according to the prior art. id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47" id="p-47"
[0047] [Fig 4] Figure 4 illustrates the stack of a radiation detector according to the invention. id="p-48" id="p-48" id="p-48" id="p-48" id="p-48" id="p-48" id="p-48" id="p-48"
[0048] [Fig 5] Figure 5 illustrates a preferred variant of a stack of a radiation detector according to the invention. id="p-49" id="p-49" id="p-49" id="p-49" id="p-49" id="p-49" id="p-49" id="p-49"
[0049] [Fig 6] Figure 6 illustrates the structure of the energy bands of a stack of a radiation detector according to the invention comprising a single intermediate layer. Figure 6a illustrates the band diagram in the pixel zone (Zdet) and Figure 6b in the interpixel zone (Zsep). id="p-50" id="p-50" id="p-50" id="p-50" id="p-50" id="p-50" id="p-50" id="p-50"
[0050] [Fig 7] Figure 7 illustrates the structure of the energy bands of a stack of a radiation detector according to the invention comprising an intermediate layer with a concentration gradient. Figure 7a illustrates the band diagram in the pixel zone (Zdet) and Figure 7b in the interpixel zone (Zsep). id="p-51" id="p-51" id="p-51" id="p-51" id="p-51" id="p-51" id="p-51" id="p-51"
[0051] [Fig 8] Figure 8 illustrates the structure of the energy bands of a stack of a radiation detector according to the invention comprising two intermediate layers. Figure 8a illustrates the band diagram in the pixel zone (Zdet) and Figure 8b in the interpixel zone (Zsep). id="p-52" id="p-52" id="p-52" id="p-52" id="p-52" id="p-52" id="p-52" id="p-52"
[0052] [Fig 9] Figure 9 illustrates the concentration of Zn atoms incorporated by diffusion into a layer of GaSb. id="p-53" id="p-53" id="p-53" id="p-53" id="p-53" id="p-53" id="p-53" id="p-53"
[0053] [Fig 10] Figure 10 illustrates the concentration of Zn atoms incorporated by diffusion into a layer of GaSb preceded by a surface layer of InAsSb.
WO 2021/122931 11 PCT/EP2020/086687 id="p-54" id="p-54" id="p-54" id="p-54" id="p-54" id="p-54" id="p-54" id="p-54"
[0054] [Fig 11] Figure 11 illustrates the simulated band diagram of an example of a stack of a detector according to the invention. id="p-55" id="p-55" id="p-55" id="p-55" id="p-55" id="p-55" id="p-55" id="p-55"
[0055] [Fig 12] Figure 12 illustrates the method for producing a radiation detector according to another aspect of the invention. id="p-56" id="p-56" id="p-56" id="p-56" id="p-56" id="p-56" id="p-56" id="p-56"
[0056] [Fig 13] Figure 13 illustrates a first variant of the method for producing a radiation detector according to the invention. id="p-57" id="p-57" id="p-57" id="p-57" id="p-57" id="p-57" id="p-57" id="p-57"
[0057] [Fig 14] Figure 14 illustrates a detector according to the invention produced by the first variant of the method according to the invention. id="p-58" id="p-58" id="p-58" id="p-58" id="p-58" id="p-58" id="p-58" id="p-58"
[0058] [Fig 15] Figure 15 illustrates a second variant of the method for producing a radiation detector according to the invention. id="p-59" id="p-59" id="p-59" id="p-59" id="p-59" id="p-59" id="p-59" id="p-59"
[0059] [Fig 16] Figure 16 illustrates a detector according to the invention produced by the second variant of the method according to the invention.

Claims (14)

WO 2021/122931 22 PCT/EP2020/086687 CLAIMS
1. A radiation detector (10) comprising a stack (Emp) of layers along a direction Z, said stack comprising:- an absorbent layer (Cabs) configured to absorb the radiation and made from a first semiconductor material (M1) having a first gap (G1) and doping of a first type (t1),- a first contact layer (Ccont) made from a second material (M2) having a second gap (G2) strictly greater than the first gap (G1),- an assembly consisting of at least one intermediate layer (Cint, Cinti), referred to as an intermediate assembly (Eint), arranged between the absorbent layer and the first contact layer, each intermediate layer (Cint, Cinti) being made from an intermediate semiconductor material (Mint, Minti) having an intermediate gap (Gint, Ginti) greater than or equal to the first gap (G1),- an upper layer (Csup) arranged on the first contact layer (Ccont) on the opposite side from said intermediate assembly, made from a third semiconductor material (M3) having a third gap (G3) strictly greater than all the other gaps of the stack,- the first contact layer and the upper layer having a plurality of detection zones (Zdet) and separation zones (Zsep), a separation zone separating one detection zone from another detection zone, each detection zone being surrounded by a separation zone in a plane perpendicular to Z, a detection zone corresponding to a pixel of said detector, the second (M2) and third (M3) materials being configured to have doping of a second type (t2) in the detection zones (Zdet) and doping of the first type (t1) in the separation zones (Zsep),- when the first doping type is n, a valence band (BVabs) of the first material (M1) is strictly less than a valence band (BVcont) of the second material (M2) in the detection zones, and the valence band or bands (BVinti) of the intermediate material or materials lie between the valence band (BVabs) of the first material and the valence band (BVcont) of the second material in the detection zones, and are configured to vary monotonically increasingly in the direction from the absorbent layer (Cabs) toward the first contact layer (Ccont),
2.WO 2021/122931 23 PCT/EP2020/086687 - when the first doping type is p, a conduction band (BCabs) of the first material (M1) is strictly greater than a conduction band (BCcont) of the second material in the detection zones, and the conduction band or bands (BCinti) of the intermediate material or materials (Mint) lie between the conduction band (BCabs) of the first material and the conduction band (BCcont) of the second material in the detection zones, and are configured to vary monotonically decreasingly in the direction from the absorbent layer (Cabs) toward the first contact layer (Ccont),- a passivation layer (Cpass) made from a dielectric material (Mdiel), arranged on the upper layer (Csup) and having openings (Op) at the level of the detection zones of the upper layer,- the semiconductor layers of the stack being compounds based on elements of groups IIIA and VA of the periodic table of the elements, the second material (M2) comprising the VA element antimony (Sb) and the third material (M3) not comprising the VA element antimony (Sb).2. The detector as claimed in the preceding claim, wherein when the first doping type is n, the valence band(s) (BVint) of the intermediate material or materials (Mint, Minti) are less than the conduction band (BCcont) of the second material (M2),and wherein when the first doping type is p, the conduction band(s) of the intermediate material or materials are greater than the valence band (BVcont) of the second material.3. The radiation detector as claimed in one of the preceding claims, wherein at the interface (12) between the upper layer and the contact layer in the detection zones,when the first doping type is n, the valence band (BVsup) of the third material lies below the valence band (BVcont) of the second material and the conduction band (BCsup) of the third material lies above the conduction band (BCcont) of the second material,and when the first doping type is p, the conduction band of the third material (BCsup) lies above the conduction band (BCcont) of the second material and the valence band (BVsup) of the third material lies below the valence band (BVcont) of the second material.
3.WO 2021/122931 24 PCT/EP2020/086687
4. The radiation detector as claimed in one of the preceding claims, wherein the third material (M3) is of the type III-As.
5. The radiation detector as claimed in one of the preceding claims, wherein the second material (M2) is GaSb and the third material (M3) is InGaAs.
6. The detector as claimed in the preceding claim, wherein the percentage of indium of the third material is less than 50%.
7. The radiation detector as claimed in one of the preceding claims, furthermore comprising:- a second contact layer (Ccont’) arranged below the absorbent layer and on the opposite side from the intermediate layer, made from a fourth semiconductor material (M4) having a fourth gap (G4) strictly greater than the first gap (G1) and doping of the first type,- a substrate (Sub) on which the second contact layer (Ccont’) is deposited.
8. The radiation detector as claimed in one of the preceding claims, wherein the doping of the second type of the detection zones is obtained by incorporation of dopant atoms (Ad) into the contact layer and the upper layer, which is carried out after the growth of said contact layer and upper layer, and via said openings.
9. The radiation detector as claimed in the preceding claim, wherein the upper layer (Csup) and the first contact layer (Ccont) have, in the detection zones and over their entire respective thickness, a quantity of dopant atoms (Ad) greater than 1017 atoms/cm3.
10. A method (30) for producing a radiation detector, comprising:- a step (100) of producing a stack (Emp) of layers along a direction Z on a substrate (Sub), comprising:- - an absorbent layer (Cabs) configured to absorb the radiation and made from a first semiconductor material (M1) having a first gap (G1) and doping of a first type (t1),- - a first contact layer (Ccont) made from a second material (M2) having a second gap (G2) strictly greater than the first gap (G1),- - a second contact layer (Ccont’) made from a fourth semiconductor material (M4) having a fourth gap (G4) strictly greater than the first gap (G1) and doping of the first type, arranged between the substrate and the absorbent layer, WO 2021/122931 25 PCT/EP2020/086687 - - an assembly consisting of at least one intermediate layer (Cint, Cinti), referred to as an intermediate assembly (Eint), arranged between the absorbent layer and the first contact layer, each intermediate layer (Cint, Cinti) being made from an intermediate semiconductor material (Mint, Minti) having an intermediate gap (Gint, Ginti) greater than the first gap (G1),- - an upper layer (Csup) arranged on the first contact layer (Ccont) on the opposite side from said intermediate assembly, made from a third semiconductor material (M3) having a third gap (G3) strictly greater than all the other gaps of the stack,- - a passivation layer (Cpass) made from a dielectric material (Mdiel), arranged on the upper layer (Csup),- - the semiconductor layers of the stack being compounds based on elements of groups IIIA and VA of the periodic table of the elements, the second material (M2) comprising the VA element antimony (Sb) and the third material (M3) not comprising the VA element antimony (Sb),- - the second and third materials being configured to have doping of the first type,- - when the first doping type is n, a valence band (BVabs) of the first material (M1) is strictly less than a valence band (BVcont) of the second material (M2) in the detection zones, when the first doping type is p, a conduction band (BCabs) of the first material (M1) is strictly greater than the conduction band (BCcont) of the second material in the detection zones,- a step (200) of forming openings (Op) in the passivation layer (Cpass),- a step (300) of incorporating dopant atoms (Ad) into the first contact layer (Ccont) and into the upper layer (Csup) via the openings (Op), so as to form detection zones (Zdet) having a second doping type, the detection zones being separated by separation zones (Zsep) separating one detection zone from another detection zone, each detection zone being surrounded by a separation zone in a plane perpendicular to Z, a detection zone corresponding to a pixel of said detector, the second (M2) and third (M3) materials then having doping of the second type (t2) in the detection zones (Zdet) and doping of the first type (t1) in the separation zones (Zsep),when the first doping type is n, the valence band or bands (BVinti) of the intermediate material or materials lying between the valence band (BVabs) of the first material and the valence band (BVcont) of the second material in the WO 2021/122931 26 PCT/EP2020/086687 detection zones, and being configured to vary monotonically increasingly in the direction from the absorbent layer (Cabs) toward the first contact layer (Ccont), when the first doping type is p, the conduction band or bands (BCinti) of the intermediate material or materials (Mint) lying between the conduction band (BCabs) of the first material and the conduction band (BCcont) of the second material in the detection zones, and being configured to vary monotonically decreasingly in the direction from the absorbent layer (Cabs) toward the first contact layer (Ccont),- a step (400) of metallization through the openings (Op) in order to form a first electrode (E1).
11. The method as claimed in the preceding claim, wherein the step of incorporating dopant atoms is carried out by diffusion.
12. The method as claimed in one of claims 10 and 11, wherein the first doping type is n and the dopant atom incorporated is zinc.
13. The method as claimed in one of claims 10 to 12, furthermore comprising, after the metallization step, a step (500) of connecting a reading circuit (ROIC) to said stack via said first electrode (E1).
14. The method as claimed in one of claims 10 to 12, furthermore comprising, after the step of producing the stack, a step (150) of bonding a reading circuit (ROIC) to said stack, the step (200) of forming the openings then being carried out through the reading circuit.
IL294116A 2019-12-20 2020-12-17 Radiation detector and associated manufacturing method IL294116B2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1915024A FR3105410B1 (en) 2019-12-20 2019-12-20 Radiation detector and associated manufacturing method
PCT/EP2020/086687 WO2021122931A1 (en) 2019-12-20 2020-12-17 Radiation detector and associated manufacturing method

Publications (3)

Publication Number Publication Date
IL294116A IL294116A (en) 2022-08-01
IL294116B1 true IL294116B1 (en) 2023-08-01
IL294116B2 IL294116B2 (en) 2023-12-01

Family

ID=72087851

Family Applications (1)

Application Number Title Priority Date Filing Date
IL294116A IL294116B2 (en) 2019-12-20 2020-12-17 Radiation detector and associated manufacturing method

Country Status (5)

Country Link
US (1) US20230016835A1 (en)
EP (1) EP4078690B1 (en)
FR (1) FR3105410B1 (en)
IL (1) IL294116B2 (en)
WO (1) WO2021122931A1 (en)

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IL27916A (en) 1966-06-01 1971-12-29 American Cyanamid Co Resolution of dl-6-phenyl-2,3,5,6-tetrahydroimidazo(2,1-b)thiazole
FR1601066A (en) 1966-06-18 1970-08-10
FR1501985A (en) 1966-10-03 1967-11-18 Cartonneries De Saint Germain Perfected set
IL156744A (en) 2003-07-02 2011-02-28 Semi Conductor Devices An Elbit Systems Rafael Partnership Depletion-less photodiode with suppressed dark current
IL174844A (en) 2006-04-06 2011-02-28 Semi Conductor Devices An Elbit Systems Rafael Partnership Unipolar semiconductor photodetector with suppressed dark current and method for producing the same
WO2012046676A1 (en) * 2010-10-06 2012-04-12 住友電気工業株式会社 Epitaxial wafer, light-receiving element, optical sensor device, and method for manufacturing epitaxial wafer and light-receiving element
IL225872A (en) 2013-04-22 2015-03-31 Semi Conductor Devices An Elbit Systems Rafael Partnership Semiconductor barrier photo-detector
FR3053836B1 (en) * 2016-07-08 2019-07-05 Thales RADIATION DETECTOR AND ASSOCIATED OMAGER

Also Published As

Publication number Publication date
IL294116B2 (en) 2023-12-01
FR3105410A1 (en) 2021-06-25
WO2021122931A1 (en) 2021-06-24
EP4078690B1 (en) 2023-08-30
EP4078690A1 (en) 2022-10-26
FR3105410B1 (en) 2022-01-14
IL294116A (en) 2022-08-01
US20230016835A1 (en) 2023-01-19

Similar Documents

Publication Publication Date Title
KR102221682B1 (en) A dual band photodetector and a method thereof
US8772717B2 (en) Radiation detector having a bandgap engineered absorber
US8575650B2 (en) Avalanche photodiode
US8022390B1 (en) Lateral conduction infrared photodetector
US7936034B2 (en) Mesa structure photon detection circuit
US20090179225A1 (en) Photo detector device
EP1681722A2 (en) Multilayered semiconductor substrate and image sensor formed thereon for improved infrared response
US9755091B2 (en) Dual-band infrared detector and method of detecting multiple bands of infrared radiation
US8178863B2 (en) Lateral collection architecture for SLS detectors
US8729602B2 (en) Avalanche photodiode
US9748427B1 (en) MWIR photodetector with compound barrier with P-N junction
US9673240B2 (en) Low cross-talk for small pixel barrier detectors
IL294116A (en) Radiation detector and associated manufacturing method
Rogalski Dual-band infrared detectors
WO2013157180A1 (en) Solid-state imaging device and manufacturing method thereof
US8022494B2 (en) Photodetector and manufacturing method thereof
CN106784075B (en) Adjustable IV races infrared photoelectric detector of investigative range and preparation method thereof
KR102284627B1 (en) Light receiving semiconductor device and manufacturing method thereof
CN112216767B (en) Fabrication of semiconductor photosensitive device
US20240234477A9 (en) Method for fabricating radiation-hardened heterojunction photodiodes
US20240136388A1 (en) Method for fabricating radiation-hardened heterojunction photodiodes
CN118248764A (en) Photodiode device, photodetector, and method of forming photodiode device
JP5840408B2 (en) Infrared sensor
CN117747708A (en) Photodiode, manufacturing method thereof and electronic element
Leeb et al. Very-Long-Wavelength Quantum Well Infrared Photodètector